/*
 * Kuzzle, a backend software, self-hostable and ready to use
 * to power modern apps
 *
 * Copyright 2015-2022 Kuzzle
 * mailto: support AT kuzzle.io
 * website: http://kuzzle.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

"use strict";

function memoize(fn, resolver = null) {
  const memoized = (...args) => {
    const key = memoized.resolver !== null ? memoized.resolver(args) : args[0];

    let result = memoized.cache.get(key);

    if (result === undefined) {
      result = memoized.fn(...args);
      memoized.cache.set(key, result);
    }

    return result;
  };

  memoized.fn = fn;
  memoized.cache = new Map();
  memoized.resolver = resolver;

  return memoized;
}

module.exports = memoize;
